Yang Tao, Ma Tian-Ci, Ye Xiao-Juan, Zheng Xiao-Hong, Jia Ran, Yan Xiao-Hong, Liu Chun-Sheng
College of Electronic and Optical Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
Phys Chem Chem Phys. 2024 Jan 31;26(5):4589-4596. doi: 10.1039/d3cp04976k.
Multivalent-ion batteries have garnered significant attention due to their high energy density, low cost, and superior safety. Calcium-ion batteries (CIBs) are regarded as the next-generation energy storage systems for their abundant natural resources and bivalent characteristics. However, the absence of high-performance anode materials poses a significant obstacle to the progress of battery technology. Two-dimensional (2D) Dirac materials have excellent conductivity and abundant active sites, rendering them promising candidates as anode materials. A novel 2D Dirac material known as "graphene+" has been theoretically reported, exhibiting prominent properties including good stability, exceptional ductility, and remarkable electronic conductivity. By using first-principles calculations, we systematically investigate the performance of graphene+ as an anode material for CIBs. Graphene+ exhibits an ultra-high theoretical capacity (1487.7 mA h g), a small diffusion barrier (0.21 eV), and a low average open-circuit voltage (0.51 V). Furthermore, we investigate the impact of the electrolyte solvation on the performance of Ca-ion adsorption and migration. Upon contact with electrolyte solvents, graphene+ exhibits strong adsorption strength and rapid migration of Ca-ions on its surface. These results demonstrate the promising potential of graphene+ as a high-performance anode material for CIBs.
多价离子电池因其高能量密度、低成本和卓越的安全性而备受关注。钙离子电池（CIBs）因其丰富的自然资源和二价特性，被视为下一代储能系统。然而，缺乏高性能负极材料对电池技术的发展构成了重大障碍。二维（2D）狄拉克材料具有优异的导电性和丰富的活性位点，使其成为负极材料的有前景的候选者。理论上报道了一种新型的二维狄拉克材料“石墨烯+”，它具有良好的稳定性、出色的延展性和显著的电子导电性等突出特性。通过第一性原理计算，我们系统地研究了“石墨烯+”作为CIBs负极材料的性能。“石墨烯+”表现出超高的理论容量（1487.7 mA h g）、较小的扩散势垒（0.21 eV）和较低的平均开路电压（0.51 V）。此外，我们研究了电解质溶剂化对钙离子吸附和迁移性能的影响。与电解质溶剂接触时，“石墨烯+”在其表面表现出很强的吸附强度和钙离子的快速迁移。这些结果表明“石墨烯+”作为CIBs高性能负极材料具有广阔的潜力。
